Reduction mechanism in the dielectric constant of fluorine-doped silicon dioxide film

Sang Woo Lim, Yukihiro Shimogaki, Yoshiaki Nakano, Kunio Tada, Hiroshi Komiyama

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

One solution to signal delay in very large-scale integrated circuits is to use a low dielectric constant interlayer film, such as F-doped silicon dioxide (SiO2). By adding CF4 to SiH4/N2O plasma-enhanced chemical vapor deposition, we obtained F-doped SiO2 films with a dielectric constant as low as 2.6. We studied the mechanism behind this decrease in the dielectric constant by estimating the constants due to each polarization component (ionic, electronic, and orientational) using capacitance-voltage (C-V) measurements, Fourier transform infrared spectroscopy spectra combined with the Kramers-Kronig relation, and spectroscopic ellipsometry. The Kramers-Kronig calculations showed that ionic polarization decreased with increasing CF4 concentration, whereas the electronic polarization remained almost constant. However, the low dielectric constant obtained by the C-V measurements could not be completely explained by the reduction in ionic and electronic polarizations but probably resulted front a decrease in the orientational polarization. Orientational polarization may be caused by Si-OH bonds and is mainly decreased by adding CF4. Therefore, an effective way to reduce the dielectric constant in F-doped SiO2 films is to reduce the orientational polarization.

Original languageEnglish
Pages (from-to)2531-2537
Number of pages7
JournalJournal of the Electrochemical Society
Volume144
Issue number7
DOIs
Publication statusPublished - 1997 Jul

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry

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